Online Documentation for SQL Query for InterBase/FireBird
If necessary, you can group the data in grid by any of the columns.
This operation is performed by dragging the column header to the Group Box area at the top. In order to display this area, you can right-click the grid and select the Show Group Box item of the context menu.
When grouping by a column is applied to the grid, all the records are displayed as subnodes to the grouping row value as displayed in the screenshot below. To reverse grouping, just drag the column header back.